China's Space Program Thread II

[gelgoog]

The CZ-8 is a replacement for the CZ-3A. It uses the boosters and center core of the CZ-7. The upper stage of the CZ-3A. The factories and tooling are the same as those used for the older hypergolic rockets. It uses the same launch pad as the CZ-7. How much could it have cost to develop anyway? Next to nothing. You basically use the CZ-8 when you need to launch a smaller satellite than you would with the CZ-7.
The CZ-8 uses two or four less side boosters and engines than the CZ-7. So it should be cheaper to produce.

These rockets were meant to be a low cost and low risk replacement for the older rockets which made (and still make) the bulk of the Chinese launches. Without the toxic hypergolic fuel. Their development was also fairly successful, with only one single failed launch of the initial CZ-7A.

Back when the program was initially conceived reusable rockets weren't even a thing anyway. Even today the economics of reusable rockets are still questionable. Outside of SpaceX no one knows the real numbers. If anything I wish they had replaced the older rockets with these ones already. As is they lack the launch pads and assembly buildings to launch more of them.

There are also plans to eventually make a reusable CZ-8 rocket for small payloads.

 

[tacoburger]

The CZ-8 is a replacement for the CZ-3A.

And yet it has barely made an dent in the number of CZ-3 launches. Hell, the CZ-8 didn't even launch a single time last year.

The upper stage of the CZ-3A. The factories and tooling are the same as those used for the older hypergolic rockets. It uses the same launch pad as the CZ-7. How much could it have cost to develop anyway? Next to nothing. You basically use the CZ-8 when you need to launch a smaller satellite than you would with the CZ-7.
The CZ-8 uses two or four less side boosters and engines than the CZ-7. So it should be cheaper to produce.

Funny how you question Spacex for not knowing their numbers but somehow come up with the conclusion based on no hard facts that development of the CZ-8 and it's variants cost basically nothing. This is rocket science, things are rarely so simple. I can point you to another few well known rocket program that reused legacy hardware and tooling in an effort to reduce costs but instead cost have ballooned to around 25 billion and more than 1 billion USD per launch, somehow. There's so many examples of it, both hardware and software.

It's a well known fact about project management that sometimes a clean slate design is needed. You can't always take a decade old design and endlessly stretch it for a task that it wasn't designed for, it often ends up costing much more then the clean slate design.

Back when the program was initially conceived reusable rockets weren't even a thing anyway.

So you admit that the program took more then 4 years? The salary/manpower cost alone means that your claim of "next to nothing" is bullshit. You focus on the tooling, but staff cost money too, that's why software development can cost billion despite not needing much hardware, hiring hundreds of people and paying them for years can cost alot of money.

And I'm mainly talking about the upgraded variant of the CZ-8, that must have been started development after the Faclon 9 proved it's worth. And of course the CZ-12, they probably haven't been working on it for more then 8 years. And projects can be cancelled or changed. Plenty of American oldspace rockets have been cancelled due to the success of SpaceX eating the American launch market. Just look at the LM-9, they got the memo pretty quickly and changed designs.

Even today the economics of reusable rockets are still questionable. Outside of SpaceX no one knows the real numbers. If anything I wish they had replaced the older rockets with these ones already.

The results speak for themselves. Spacex is putting more mass into orbit then every other space agency combined.

These rockets were meant to be a low cost and low risk replacement for the older rockets which made (and still make) the bulk of the Chinese launches. Without the toxic hypergolic fuel. Their development was also fairly successful, with only one single failed launch of the initial CZ-7A.

The issue is that the LM-6/7/8 didn't make anywhere near a dent in the number of hypergolic launches for some reason. And in 2024, despite a wave of reusable rockets 2-3 years away, they're still working on an upgraded version of the LM-6/8 and CZ-12. Might have been more useful 20 years ago.

I want the hypergolic rockets to go too, but it's clear that the only thing that's going to dislodge them is a Falcon 9 tier workhorse rocket, and the route to achieving that would be faster if money and manpower wasn't spent on useless side projects. I have no problem with the LM-6/7/8, but why spent the resources the upgraded LM-6C and LM-8G and the LM-12 when it must have been clear that resauble rockets were going to dominate the launch market?

There are also plans to eventually make a reusable CZ-8 rocket for small payloads.

Probably scrapped seeing as there has been no new about it for like 6 years, I have been paying attention for every one of those years. And for good reason, the CZ-8 would have needed a complete redesign of it's engine layout, considering that the optimal reusable engine layout that we know of is a larger cluster of even numbered engines. Not the two engine and two boosters configuration that the CZ-8 has. And at that point, you might as well just make a new rocket from stratch.

Like I said, at that point it's just easier to make a clean slate design. It's like trying to make an aircraft by strapping wings to a car. You're "saving" money by using an existing hull and engine, but the amount of work needed to make an horrible aircraft means that it would be faster and cheaper to start from stratch.

 

[gelgoog]

I already told you the reason why they are not launching more CZ-7/8 rockets. There is a single launch pad they can operate from, plus only one single rocket and satellite integration building.

The idea that because the medium rocket took a long time to show up in use means it must have cost a lot of money to design and develop is fanciful. Half of the cost of designing a rocket is the engines. And these medium rockets use the same first stage engines as the CZ-5 boosters. The same production facilities as the hypergolic rockets. I would bet the biggest cost was making the launch pad. Not developing the rockets. Development of the Chinese Space Station was a national priority. So of course the rockets which support the construction of the space station (CZ-5) and servicing it with the Tianzhou (CZ-7) were given higher priority than something like the CZ-7A or CZ-8. CZ-7A and CZ-8 basically added the CZ-3 upper stage so you could repurpose the basic medium rocket to also launch regular satellites to GTO and SSO. The plan to design this family of rockets is probably at least two decades old. Back then the most advanced launchers in use were the Ariane 5, plus the EELVs like the Delta IV and Atlas V. Progress in the new Chinese launcher program happened rhythmically despite the massive technological gap between this generation of rockets and the previous one. The Chinese national goal of developing the manned space station was achieved. A highly successful program.

The basic engine technology in the YF-100 can even be repurposed to make reusable rockets like the CZ-10. So I don't know what is your problem really. If anything China was the first country to announce a reusable rocket program after SpaceX had success with their own Falcon 9 program. And it's probably the program that is furthest ahead of all of those competitor programs.

I think redesigning the CZ-9 to use LOX/LCH4 engines is a big mistake. They had already developed the YF-130 engine. They could have just designed a reusable variant without changing the engine. It will add further delays and issues to the design for little reason. It can take a decade to develop a rocket engine. Seven YF-130 engines would have similar power to a Saturn V first stage.

 

[by78]

A new research base for space environmental simulation has been handed over for initial operations. The base is located in the great city of Harbin, and it holds various equipment used to simulate multiple types of space and extraterrestrial environmental factors such as vacuum, space radiation, extreme temperature swings, martian and lunar dust environments, etc. The base is a major piece of infrastructure for verifying environmental compatibility of satellites and other space-based hardware, and it can also be used to carry out experiments that otherwise would need to be conducted in space.

The research base (located in Harbin) for space environmental simulation has officially passed acceptance and begun formal operation. It will be used to simulate nine major types of space and extraterrestrial environments and environmental factors such as vacuum, space radiation, extreme temperature swings, martian and lunar dust environments, etc. The base is a major piece of infrastructure for verifying environmental compatibility of satellites and other space-based hardware, and it can also be used to carry out experiments that otherwise would need to be conducted in space.

 

[huemens]

I think redesigning the CZ-9 to use LOX/LCH4 engines is a big mistake. They had already developed the YF-130 engine. They could have just designed a reusable variant without changing the engine.

Probably because YF-130 is too powerful to land back the empty booster.

 

[taxiya]

Probably because YF-130 is too powerful to land back the empty booster.

no. The YF-130 version of CZ-9 has 12 YF-130 in the first stage. Running on single engine at landing gives 1/12 of total thrust. For comparison Falcon 9 is 1/9, CZ-10A is 1/7. CZ-9's YF-130 would be relatively less powerful than both Falcon 9 and CZ-10A, in other words easier to make vertical landing without demanding deep throttling.

The problem with this CZ-9 is the 12 engines are spreaded in 5 fuselages, the core has 4 engines making it not ideal of running on single engine, the thrust is off center. Remember this design was before "reuse" is a thing.

The newer version of CZ-9 with YF-135 and YF-209 (methane) is intended for vertical landing though.

Anyway, I think reusability is really exaggerated beyond necessity. People have become "making every rocket reusable only for the sake of trend and fasion and brag with Elon Musk". A falcon 9 sized (more or less) reusable rocket is a good idea. The size of Starship or CZ-9 or SLS block II, seriously? Who really has some many hundreds tonnes of mass to throw into earth orbit many times every year?

 

[Blitzo]

no. The YF-130 version of CZ-9 has 12 YF-130 in the first stage. Running on single engine at landing gives 1/12 of total thrust. For comparison Falcon 9 is 1/9, CZ-10A is 1/7. CZ-9's YF-130 would be relatively less powerful than both Falcon 9 and CZ-10A, in other words easier to make vertical landing without demanding deep throttling.

The problem with this CZ-9 is the 12 engines are spreaded in 5 fuselages, the core has 4 engines making it not ideal of running on single engine, the thrust is off center. Remember this design was before "reuse" is a thing.

The newer version of CZ-9 with YF-135 and YF-209 (methane) is intended for vertical landing though.

Anyway, I think reusability is really exaggerated beyond necessity. People have become "making every rocket reusable only for the sake of trend and fasion and brag with Elon Musk". A falcon 9 sized (more or less) reusable rocket is a good idea. The size of Starship or CZ-9 or SLS block II, seriously? Who really has some many hundreds tonnes of mass to throw into earth orbit many times every year?

I think ultimately the reusability question is as about tonnage to orbit.
Reusability of super heavy launchers is just one way of trying to attain low cost, high frequency, large singular payload launches.

It is basically a question of whether "build them and they will come" is viable (i.e. satellite and payload manufacturers will develop the payloads to make use of the launch capacity), or whether having that kind of launch capability would be a waste because there is nothing that needs to be launched.


I think it is way too early to call it yet, but to be on the safe side, every nation and space company really should be erring on the side of caution because in the long term we don't know how the economics and industry capability will pan out.

 

[tiancai8888]

A famous insider say the satellite of yesterday's launch is the first service satellite of GW constellation

 

[Asug]

It would be good to know the parameters of the final orbit. As far as we know, the GW project did not envision satellites in highly elliptical orbits. Has something changed, or does this message require clarification?

 

[by78]

A LM-3B successfully launched an internet satellite (卫星互联网高轨卫星01星) into orbit. This was the 510th flight of the Long March series.